The present invention relates to a disk-type signal processing apparatus which makes use of a disk-type recording medium such as a video disk, audio disk, optical disk and so forth. More particularly, the present invention is concerned with a recording medium loading mechanism for use in the disk-type signal processing apparatus of the type mentioned above, which is improved to simplify the mechanism of the apparatus and the electric circuit thereof.
Automatic loading devices for loading a recording medium, such as a disk cartridge, in a signal processing apparatus have been known from Japanese Utility Model Unexamined Publication Nos. 61-90052 and 60-146951. In general, the known loading device includes a cartridge holder portion, a driving motor with gears, and a driving power transmission. In particular, the driving power transmission includes a lot of component parts such as a link mechanism, a gear train, a power transmission shaft and so forth. The loading and unloading operation for loading and unloading the disk cartridge on and from the signal processing apparatus is effected by controlling the driving motor in forward and backward directions. Therefore, the driving circuit for the driving motor is required to have a protection circuit for checking the reverse current which is produced when the direction of the driving electric current is changed to reverse the driving motor. Furthermore, the mechanism sections which operate during the loading and unloading operations are made from materials having a high degree of reliability for longer operation, because only limited elements of these sections, such as the motor and gears, are actually used repeatedly.
As pointed out above, the known loading device has a driving power transmission having a larger number of component parts. This requires a complicated driving circuit for the driving motor as well as mechanical parts that have to be made from highly reliable materials. Satisfying these requirements runs contrary to the demands for reduction in the cost and size and for improvement in the reliability of disk players.